JERUSALEM — The Palestinian death toll from Israel’s massive air campaign in Gaza topped 100 people Friday as rockets fired by militants reached deeper into Israel — and for the first time in the fighting, struck from neighboring Lebanon.

Gaza militants already have fired more than 550 rockets against Israel in the offensive. The Israeli military says it has hit more than 1,100 targets, mostly what it identified as rocket-launching sites, bombarding the territory on average every five minutes.

In Gaza, an Israeli airstrike Friday hit the home of a well-known Islamic Jihad leader. Gaza health officials said strikes overnight killed a total of eight people, raising the death toll to at least 98. A later strike pushed the tally over 100, and some 670 have been wounded, officials said.

In the southern Gaza city of Rafah, residents sifted through the remains of a four-story building that was struck, and scattered for cover as another airstrike landed nearby.

Rocket fire continued in earnest from Gaza toward various locations in southern and central Israel, including Israel’s international airport. The commercial center of Tel Aviv and Ben-Gurion airport also heard warning sirens Friday, but these rockets were intercepted and there was no disturbance to Israel’s air traffic. Hamas says it intends to fire rockets at the airport and warned foreign airlines to stop flying to Israel.

Palestinians look at the remains of a missile which witnesses said was fired by an Israeli aircraft on a street in Deir El-Balah in the central Gaza Strip.Photo: Reuters

Israel has shot down at least 110 incoming rockets so far with its “Iron Dome” defense system.

Gaza rocket fire struck a gas station in southern Israel, seriously wounding one person and sending large plumes of smoke into the air.

In northern Israel, rocket fire struck near the Lebanese border and the military responded with artillery fire toward the source in southern Lebanon, military spokesman Lt. Col. Peter Lerner said.

The Lebanese military said militants there fired three rockets toward Israel around 6 a.m. (11 p.m. EDT) and the Israelis retaliated by firing about 25 artillery shells on the area.

Lebanon’s state-run National News Agency said one of the militants firing the rockets was wounded and was rushed to a hospital. The Lebanese military said troops found two rocket launchers and dismantled them.

Palestinian firefighters walk around a boat hit in a missile strike at the port in Gaza City.Photo: AP Photo

Southern Lebanon is a stronghold of the Shiite militant group Hezbollah, which has battled Israel numerous times. However, recent fire from Lebanon has been blamed on radical Palestinian factions in the area and Hezbollah has not been involved in the ongoing offensive.

A pair of Lebanon-based al Qaeda-linked groups, the Battalions of Ziad Jarrah and the Abdullah Azzam Brigades, have claimed responsibility in the past for similar rocket attacks on Israel.

Israel launched the Gaza offensive to stop incessant rocket fire that erupted after three Israeli teenagers were kidnapped and killed in the West Bank and a Palestinian teenager was abducted and burned to death in an apparent reprisal attack.

Lerner said the military was doing its utmost to prevent civilian casualties, calling inhabitants ahead of time to warn of imminent attacks. He said Israeli forces also fire “non-explosive munitions” at roofs as a warning and looks for people to leave before destroying a structure.

A man holds a mock Qassam rocket during a rally organized by Lebanese and Palestinian supporters of the Islamist movement Hamas and the Islamic group Jamaa Islamiya.Photo: Getty Images

Lerner blamed Hamas for the death of innocent bystanders by firing from heavily populated areas.

Israel’s military “uses its weapons to defend its civilians. Hamas uses its civilians to defend its weapons,” he said.

Military chief Lt. Gen. Benny Gantz said Hamas was “sinking into its own disaster,” while Israel was deploying its military might “not without reasoning, not without thinking, not without taking into account there are civilians in Gaza.”

Israeli leaders are mulling whether to launch a ground assault in Gaza to target Hamas. Such a move, though, would likely involve a rise in Palestinian civilian casualties and put Israeli troops at risk as well. Israel has mobilized more than 30,000 reservists to supplement the potential ground operation.

During a ground incursion in early 2009, hundreds of civilians were killed and both sides drew war crimes accusations in a United Nations report.

Middle East envoy Tony Blair said efforts were being made to try to reach a truce.

“We are in a critical point,” he said. “I think we have got to do everything we can to … create a situation in which the people in Gaza and the West Bank and in Israel feel that this is not then going to recur and there is some genuine plan in place.”

Citizens take part in a demonstration to show solidarity with Palestinians near the Israeli embassy in Brussels, Belgium.Photo: EPA